I'm not a big fan of a puzzles but this one is a real nice polished demo! I really liked it! Hints and ability to skip a level is such a nice thing to have.
Probably the only bit of feedback that I can give is that
No one really needs that long of a cutscene at the beginning. When you show that the PC jumps out of the pile I would assume I can control it immediately after.
Also I would want to see the ability to start new game in-game, not by tinkering with the save file. I love that you encourage more intimate approach to the game... But you get the point :)